fix: gracefully handle validating an array when a hash is expected

lib/pact_broker/api/contracts/base_contract.rb

@@ -22,7 +22,8 @@ class BaseContract < Dry::Validation::Contract
         # @param [Hash] the parameters to validate
         # @return [Hash] the validation errors to display to the user
         def self.call(params)
-          format_errors(new.call(params&.symbolize_keys).errors)
+          params_to_validate = params.respond_to?(:symbolize_keys) ? params.symbolize_keys : params
+          format_errors(new.call(params_to_validate).errors)
         end
       end
     end

spec/lib/pact_broker/api/contracts/base_contract_spec.rb

@@ -0,0 +1,26 @@
+require "pact_broker/api/contracts/base_contract"
+
+module PactBroker
+  module Api
+    module Contracts
+      describe BaseContract do
+
+        class TestContract < BaseContract
+          json do
+            required(:name).filled(:string)
+          end
+        end
+
+        describe ".call" do
+          context "when an array is supplied" do
+            subject { TestContract.call([1]) }
+
+            it "doesn't blow up" do
+              expect(subject[:name]).to eq ["is missing"]
+            end
+          end
+        end
+      end
+    end
+  end
+end